Major refactor of identity service & tests, make jsx/dom as identity view renderer

[byn9826]

BREAKING CHANGES:

1. The following properties have been removed from wrangler.toml and are now defined as an enum in configs/branding.ts:

• FontFamily, FontUrl, LayoutColor, LabelColor, PrimaryButtonColor, PrimaryButtonLabelColor, PrimaryButtonBorderColor, SecondaryButtonColor, SecondaryButtonLabelColor, SecondaryButtonBorderColor, CriticalIndicatorColor.
• This change helps ensure that the total number of environment variables does not exceed the maximum allowed for a Cloudflare free plan.

2. The required version for Wrangler is now "3.112.0". Using an older version might cause issues with certain Wrangler commands.
3. For the local environment, you must set the ENVIRONMENT variable to "dev" in the .dev.var file. For remote environments or Node-built versions, ENVIRONMENT should be set to any value other than "dev".